When an X-ray penetrates an object of interest, information about the structure of the object of interest is conveyed in the form of attenuation, phase, and scatter components of the X-ray. Conventional detectors integrate the scatter and phase changes, so that the attenuation image does not display the phase or scatter information. Recent interferometric approaches have made it possible to derive the phase and scatter components of the X-ray image, and so more information about the structure of an imaged object of interest can be obtained.
Dark-field scattering refers to the process of an X-ray beam being scattered due to microstructure in an object of interest. The dark-field effect normally is not visible, because a conventional attenuation X-ray image effectively acts to perform a line integration of the scattered X-rays. With a specially adapted interferometer placed before the X-ray detector, a scattering component of the X-ray radiation may be separated from an attenuation radiation and a phase modulated component.
WO 2014/002026 A1 discusses a method for dark-field imaging including acquiring dark-field image projections of an object with an imaging apparatus. Such imaging methods can, however, be further improved.